How to set foreign key nullable

Question

I have a class configuration something like the following(just a sample not actual meaning) -

public class payment
{
    @Id
    @Column("payment_id")
    private int paymentId;

    @ManyToOne
    @JoinColumn(name ="")
    private Fine fine;
    //getter setter and other stuff
}

public class Fine{
    @Id
    @Column("fine_id")
    private int fineId;

    @Column("amount")
    private int fineAmount;

    //other stuff
}

I am getting org.hibernate.ObjectNotFoundException: No row with the given identifier exists error message. In accordance with the answer it is because a foreign key cannot have null value but my db contains null. I cant change the db or project structure so is there any way so that i can issue null value to my foreign key 'legally' ie without creating an exception.

Possible duplicate of [Cannot make @ManyToOne relationship nullable](https://stackoverflow.com/questions/15511899/cannot-make-manytoone-relationship-nullable) — Markus Mauksch, Sep 11 '18 at 13:03
No reason a FK can't be null. The joinColumn annotation has an attribute nullable=true, did you try that? — Nathan Hughes, Sep 11 '18 at 13:05
@NathanHughes using `nullable` doesnt help as the field still remains not-nullable — monster, Sep 11 '18 at 13:16
@MarkusMauksch lemme look into the solution if it works, thanks anyways — monster, Sep 11 '18 at 13:17
@monster looks like your solution should be in there. no use in having the answer on two different pages :) — Markus Mauksch, Sep 11 '18 at 13:20

score 0 · Answer 1 · answered Sep 12 '18 at 13:15

0

Using @Column(nulable = true)

Is used for creation of DDL scripts and does not bring the desired behavior.

You need to mark the @ManyToOne as optional.

@ManyToOne(optional = true)

answered Sep 12 '18 at 13:15

Sklo

51
4

How to set foreign key nullable

1 Answers1